drm/i915: Handle YUV subpixel support better

Y41x formats is a 4:4:4 format, so it can be addressed with pixel level accuracy.
Meanwhile it seems that while rotating YUYV 4:2:2 formats need a multiple of 2
for width and height, otherwise corruption occurs.

For YUV 4:2:2, the spec says that w/h should always be even, but we get
away with odd height while unrotated. When rotating it seems corruption
occurs with an odd x/y, and w/h should always be even.
Just to be completely paranoid, reject odd x/y w/h when rotating 90/270.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190322135954.20434-1-maarten.lankhorst@linux.intel.com
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 3f2055f70d05123313e769b7e328ed4615973047..aca987356194b8af3a060d197a2c78780ebd575d 100644 (file)
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -269,7 +269,8 @@ int intel_plane_check_src_coordinates(struct intel_plane_state *plane_state)
 {
        const struct drm_framebuffer *fb = plane_state->base.fb;
        struct drm_rect *src = &plane_state->base.src;
-       u32 src_x, src_y, src_w, src_h;
+       u32 src_x, src_y, src_w, src_h, hsub, vsub;
+       bool rotated = drm_rotation_90_or_270(plane_state->base.rotation);
 
        /*
         * Hardware doesn't handle subpixel coordinates.
@@ -287,18 +288,26 @@ int intel_plane_check_src_coordinates(struct intel_plane_state *plane_state)
        src->y1 = src_y << 16;
        src->y2 = (src_y + src_h) << 16;
 
-       if (fb->format->is_yuv &&
-           (src_x & 1 || src_w & 1)) {
-               DRM_DEBUG_KMS("src x/w (%u, %u) must be a multiple of 2 for YUV planes\n",
-                             src_x, src_w);
+       if (!fb->format->is_yuv)
+               return 0;
+
+       /* YUV specific checks */
+       if (!rotated) {
+               hsub = fb->format->hsub;
+               vsub = fb->format->vsub;
+       } else {
+               hsub = vsub = max(fb->format->hsub, fb->format->vsub);
+       }
+
+       if (src_x % hsub || src_w % hsub) {
+               DRM_DEBUG_KMS("src x/w (%u, %u) must be a multiple of %u for %sYUV planes\n",
+                             src_x, src_w, hsub, rotated ? "rotated " : "");
                return -EINVAL;
        }
 
-       if (fb->format->is_yuv &&
-           fb->format->num_planes > 1 &&
-           (src_y & 1 || src_h & 1)) {
-               DRM_DEBUG_KMS("src y/h (%u, %u) must be a multiple of 2 for planar YUV planes\n",
-                             src_y, src_h);
+       if (src_y % vsub || src_h % vsub) {
+               DRM_DEBUG_KMS("src y/h (%u, %u) must be a multiple of %u for %sYUV planes\n",
+                             src_y, src_h, vsub, rotated ? "rotated " : "");
                return -EINVAL;
        }